import sys


def calc(l):
    ans = []
    for i in range(len(l) - 1):
        ans.append(1 - (l[i] & l[i+1]))
    return ans

N,K = map(int,input().split())
K = N - K
S = input()
l = list(S)
l = list(map(int,l))
if K % 2 == 1:
    ll = []
    for i in range(N - 1):
        ll.append(1 - (l[i] & l[i+1]))
    l = ll
    K -= 1
    N -= 1
if K == 0:
    print(*l,sep = "")
    exit()

if K <= 10 or N <= 10:
    for _ in range(K):
        l = calc(l)
    print(*l,sep = "")
    exit()

u = K // 2
start = u
end = N - u - 1

ans = [0] * (N - K)

hidari = False
migi = False
for i in range(u):
    if l[i] == 0:
        hidari = True
        break
for i in range(end + 1,N):
    if l[i] == 0:
        migi = True
        break
"""
if l[start] == 1:
    if l[u+1] == 1:
        ans[0] = 1
    else:
        if hidari:
            ans[0] = 0
        else:
            ans[0] = 1
else:
    ans[0] = 0
if l[end] == 1:
    if l[end-1] == 1:
        ans[-1] = 1
    else:
        if migi:
            ans[-1] = 0
        else:
            ans[-1] = 1
else:
    ans[-1] = 0
"""
if l[start] == 1:
    if l[start + 1] == 1:
        ans[0] = 1
    else:
        if l[start - 1] == 1:
            ans[0] = 1
        else:
            ans[0] = 0
if l[end] == 1:
    if l[end - 1] == 0 and l[end] + 1 == 0:
        ans[-1] = 0
    else:
        ans[-1] = 1
for i in range(1,N - K - 1):
    if l[start+i] == 0:
        ans[i] = 0
        continue
    else:
        if l[start + i - 1] == 0 and l[start + i + 1] == 0:
            ans[i] = 0
        else:
            ans[i] = 1
print(*ans,sep = "")
#print(start,end)